What is the exact area of a circle whose diameter is 24 cm?

Question

misty1212 · Answer

HI!!

misty1212 · Answer

half the diameter is the radius
what is half of 24?

anonymous · Answer

12 and hi!

misty1212 · Answer

then the area is $\pi r^2$ so $$\pi\times 12^2$$

misty1212 · Answer

or if you prefer 
$$144\pi$$

anonymous · Answer

try starting off with $$Area = \pi*r^2$$

anonymous · Answer

where pi is 3.14

anonymous · Answer

and r is half of the diameter (the diameter is 24)

anonymous · Answer

so this is the equation so far 
3.14*r^2

anonymous · Answer

452.16?

anonymous · Answer

there you go. Easy enough right?

misty1212 · Answer

careful here dear!!

misty1212 · Answer

"exact" value means "exact" not a decimal approximation

misty1212 · Answer

don't go with the decimal, go with the "exact" answer $$144\pi$$

anonymous · Answer

but it is exact...

anonymous · Answer

try it on a calculator, that's what you get.

misty1212 · Answer

no dear a decimal is only an approximation for $\pi$ it is not exact

misty1212 · Answer

calculators do not give exact answers, they give decimals

anonymous · Answer

ok, then you may take it from here. *Hands baton off to @misty1212 *

misty1212 · Answer

$$3.14$$ is not $\pi$ it is an approximation of $\pi$ to only two decimal places

anonymous · Answer

A.
 576 cm2
 
 B.
 144 cm2
 
 C.
 48 cm2
 
 D.
 24 cm2
Those are the answer choices

misty1212 · Answer

are there no $\pi$'s in those answers?

anonymous · Answer

well yes but they just didnt show up

misty1212 · Answer

then go with 
$$144\pi$$

misty1212 · Answer

those $\pi$'s don't show sometimes

anonymous · Answer

Yea so 144 is the right answer?

misty1212 · Answer

yes

anonymous · Answer

ok I will give u a medal and can you give @okayd a medal because they helped. :) plz

misty1212 · Answer

sure, just did it !

anonymous · Answer

Thanks :)